Abstract: In one aspect, the present invention relates to a system for monitoring wind turbines, wherein image and acoustic monitoring, in particular, is performed. In order to further improve, for example, the maintenance, safety and efficiency of a wind turbine, it is desirable to monitor additional parameters of the wind turbine. A wind turbine is provided, wherein acoustic and optical sensors are employed to monitor the operation of the wind turbine. In one embodiment, the optical sensor images a particular location in the nacelle housing when the acoustic sensor detects a sound emanating from that location in the nacelle housing. A method for monitoring a wind turbine is described wherein when a deviation between the operating acoustic spectrum and the reference acoustic spectrum exceeds the threshold, the component that generated the operating acoustic spectrum is imaged.

Abstract: The invention relates to a volumetric control for blower filter devices in which a control unit (5) determines a differential pressure between measuring points (1, 2) that is converted into a control signal for the fan output. To this end, at least two measuring points (1, 2) are arranged in the airflow behind the fan impeller (3) and in front of the consumer, in particular, the breathing hood (4). The measuring points (1, 2) can be located in the airflow inside the case filter device behind the impeller wheel (3) and in front of the outlet of the blower filter device or one measuring point is placed in the airflow inside the housing of the case filter device behind the impeller wheel (3) and one is placed in the vicinity of the connection of the breathing hood (4) or both measuring points are located in the breathing hose (8).

Abstract: A detection system for identifying airfoils having a cooling systems with orifices that are plugged with contaminants or with showerheads having a portion burned off. The detection system measures pressures at different locations and calculates or measures a differential pressure. The differential pressure may be compared with a known benchmark value to determine whether the differential pressure has changed. Changes in the differential pressure may indicate that one or more of the orifices in a cooling system of an airfoil are plugged or that portions of, or all of, a showerhead has burned off.

Abstract: A gas turbine engine (10) comprises a fan rotor (26) having a plurality of fan blades (24) and an apparatus (34) for detecting an impact on the fan blades (24). The apparatus (34) comprises speed sensors (48,48B) arranged to measure the speed of rotation of the fan rotor (26) and the turbine rotor (58) and to produce speed signals. A processor unit (40) analyses the speed signals to determine the angle of twist between the ends of the fan rotor (26). The processor unit (40) is arranged to analyse the angle of twist to determine if the angle of twist of the fan rotor (40) oscillates by more than a predetermined level from an average level. The processor unit (40) is arranged to produce a signal indicative of an impact to at least one of the fan blades (24) if the angle of twist oscillates by more than the predetermined level and sends a signal to an indicator device (44,46).

Abstract: A method and system for detecting damage to the rotor of an aircraft engine using devices for measuring vibration and speed in order to acquire data relating to the speed of the rotor and also to the amplitude and the phase of rotor vibration during a determined flight. The method includes the following steps: reading the acquired data; calculating a mean vibration vector over a determined rotor speed range on the basis of the acquired data; calculating a vector difference between the mean vibration vector of the determined flight and the mean vibration vector of a reference flight for the rotor speed range; comparing the modulus of the vector difference with a predetermined threshold value; and issuing a warning signal when the modulus of the vector difference exceeds the predetermined threshold value, the steps being performed after the determined flight has been completed.

Abstract: A method of detecting the change in the structure of a turbine rotor uses the steps of injecting an ultrasonic signal into the turbine rotor at a first position using a first ultrasonic transducer to produce a diffuse field ultrasonic signal in the rotor; detecting the signal in the rotor at a second position using a second ultrasonic transducer measuring the time for the signal to travel from the first ultrasonic transducer to the second ultrasonic transducer and comparing the measured time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer to the second ultrasonic transducer with a stored time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer to the second ultrasonic transducer to determine if there is a change in the structure of the turbine rotor.

Abstract: A turbine for production of electric energy in flowing water, comprising a number of shaped foils (5), each foil (5) being attached with a shaft (6) to a supporting structure (3) which is connected to the main shaft (2) of the turbine, and the shaft (6) of each foil (5) being mainly parallel with the main shaft (2). Each foil (5) is equipped with a step motor (8) and encoder (16), and the main shaft (2) is equipped with an encoder (18) and circuit breaker (19); an external measuring device (22) for measuring the speed of the water (11); and a computer (23) comprising a particular computer programme, to obtain that the signals from said encoders (16,18) and said measuring device (22) being processed in said computer (23), to achieve by assistance of said step motors (8) that the angle of a main surface of each foil (5) be individually regulated into a desired direction of attack relative to the direction of said flowing water (11).

Abstract: A method and apparatus for early fault detection in a centrifugal pump equipped with a balancing device, where the balancing device has an axial gap and optionally at least one radial gap through which a balancing flow is conducted, and with a spring element which acts on the balancing device to hold open the axial gap. Reliable information regarding impending faults is obtained while largely using existing elements by measuring the deformation of the spring element (10, 14) during operation of the centrifugal pump (24), and starting from the pump characteristics of the centrifugal pump (24) and the spring constant of the spring element (10, 14), drawing a conclusion regarding the instantaneous operating state of the centrifugal pump based on the measured deformation.

Abstract: The steam-cooling-type gas turbine is provided with communication passages in number equal to that of the front-stage stator blades and the rear-stage stator blades. Many communication passages are placed in the blade ring densely. As a result, in the blade ring, the temperature difference between the portion having the communication passages and the portion without the communication passages becomes smaller. This makes it possible to minimize the thermal deformation of the blade ring, thereby making it possible to provide uniform clearance between the fixed side such as the blade ring and the rotary side members.

Abstract: A method is disclosed to monitor deflections in a turbine casing by: positioning gap sensors on a shell standard support surface and below an opposite surface of the shell arm support; each gap sensor monitoring a gap between the shell standard support surface and shell arm support; determining change in the planar slope of the shell arm support over the period of time based on the collected data, wherein changes in the slope indicate deflections in the casing.

Abstract: A control strategy for a gas turbine engine which exchanges future lifetime of the engine for present thrust. Gas turbine engines, such as those used in aircraft, sometimes incur damage, as when they ingest birds, or are struck with ballistic objects fired by an enemy. The invention detects the damage, and invokes a control strategy wherein the engine is operated in a more harsh manner, thereby sacrificing a significant part of the remaining lifetime of the engine, in order to obtain thrust currently.

Abstract: A system and method is provided for detecting and controlling rotating stall in the diffuser region of a centrifugal compressor. The process begins with the detection or sensing of acoustic energy associated with the onset of rotating stall. A pressure transducer is placed in the gas flow path downstream of the impeller, preferably in the compressor discharge passage or the diffuser, to measure the sound or acoustic pressure phenomenon. Next, the signal from the pressure transducer is processed either using analog or digital techniques to determine the presence of rotating stall. Rotating stall is detected by comparing the detected energy amount, which detected energy amount is based on the measured acoustic pressure, with a predetermined threshold amount corresponding to the presence of rotating stall. Finally, an appropriate corrective action is taken to change the operation of the centrifugal compressor in response to the detection of rotating stall.

Abstract: A system for providing power and communication signals to a device associated with a rotating component on an aircraft includes a communication strategy that allows power and command signals to be propagated along the same conductors. A stationary controller provides power and command signals to a controller that is supported for rotation with the rotating device. Only two slip rings are required to communicate power and command signals between the stationary and rotating controllers. Synchronous modulation preferably is used for sending the command signals to avoid interference from noise inherent in slip ring electrical couplings. A multi-zone propeller deicing heater is one example device that is controllable using the inventive approach.

Abstract: Supports are provided on the upper outer casing of each turbine of a turbine unit, and the upper inner casing of the turbine is temporarily placed on the supports of the upper outer casing, which is temporarily placed on the operating floor. By placing the casings temporarily in that way, a large space can be secured for the inspection of the turbine unit, and the inspection can be carried out quickly, which increases the operation ratio of the whole plant including the turbine unit. This invention is useful mainly for turbine units and their overhaul.

Abstract: A system is disclosed for adjusting a gas turbine firing temperature control algorithm and combustion reference temperature algorithms based on exhaust gas temperature, turbine pressure ratio and compressor discharge temperature for water content in the air entering the compressor differing from the design water content of ambient air. The water content in the ambient air is calculated by the control system from measured data from a dry bulb temperature sensor and a wet bulb temperature or humidity sensor.

Abstract: An infrared camera is configured to measure a temperature distribution on a surface of at least one rotating turbine bucket. With the measured surface temperature distribution, a condition index is determined which reflects either an overall condition of a bucket or a specific location on the bucket. The condition index can be used to predict the remaining useful life of a turbine bucket, which can be used to optimize maintenance intervals and thereby reduce maintenance costs.

Abstract: A cooling fan having flashing light effect, having a fan base, a set of blades and a plurality of light emitting diodes. The fan base further comprises a plurality of supporting levers connected to a common base. Circular axial perforation is formed in the common base, and a plurality of slots and light guides are installed near a periphery of the common base. Each light emitting diode is embedded in the corresponding slot and electrically connected to the circuit board of the set of blades.

Abstract: A method and apparatus for early fault detection in a centrifugal pump equipped with a balancing device, where the balancing device has an axial gap and optionally at least one radial gap through which a balancing flow is conducted, and with a spring element which acts on the balancing device to hold open the axial gap. Reliable information regarding impending faults is obtained while largely using existing elements by measuring the deformation of the spring element (10, 14) during operation of the centrifugal pump (24), and starting from the pump characteristics of the centrifugal pump (24) and the spring constant of the spring element (10, 14), drawing a conclusion regarding the instantaneous operating state of the centrifugal pump based on the measured deformation.

Abstract: The invention relates to a steam turbine (3) comprising an optical measuring system (60) for measuring a moving blade vibration. A transmitter (55) produces a light beam (61) which strikes the moving blades (27, 29, 31, 33) and is reflected by these into a receiver (57). By providing that the transmitter (55) is separated from the receiver (56), the invention achieves a measuring angle that actually reduces the scattered light effect of the steam enough to enable reliable optical measurements of the blades vibration. The invention also relates to a method for measuring the vibration of a moving blade (33) in a flow channel (19, 21, 23, 25) of a steam turbine (3).

Abstract: A system for determining whether a centrifugal pump assembly is degraded as operating outside of acceptable operating limits and includes a processor adapted by software to perform the steps of automatically characterizing the pump characteristics at a predetermined operating level and testing for degradation using the automatically acquired pump characteristics.

Abstract: A method for forming a monitoring deposit on a substrate comprises determining a temperature range to subject the substrate to provide a high temperature of operation up to less than a critical substrate deterioration temperature; selecting a binder to monitor temperature by emitting an indicator within the determined temperature range; combining the indicator and the binder; and applying the combined indicator and binder to the substrate to form the monitoring deposit. An article comprises a substrate; and a combined indicator and binder applied into the substrate, wherein the binder emits the indicator within a temperature range determined to subject the substrate to high temperature operation up to less than a critical substrate deterioration temperature.

Abstract: A protective device is provided for protecting a turbo molecular pump having a rotor mounted for undergoing rotation, an intake port for sucking gas by rotation of the rotor, and an exhaust port for exhausting the gas sucked from the intake port. The protective device has a detecting device for detecting the occurrence of an abnormal phenomenon in the turbo molecular pump. An abnormal phenomenon inference device infers a type of the abnormal phenomenon detected by the detecting device. A value obtaining device infers a magnitude of damage given to the turbo molecular pump by the abnormal phenomenon inferred by the abnormal phenomenon inference device and obtains a value weighted based on the inferred magnitude of the damage. A value accumulation device accumulates the value obtained by the value obtaining device. A sum obtaining device obtains a sum of the values accumulated in the value accumulation device.

Abstract: A turbomolecular pump (10) comprises a stator, a pump rotor, a motor (28) for driving the pump rotor and a control device (42). The control device (42) controls the motor output power such that the motor output power does not exceed a permissible maximum motor output power. On the stator side of the turbomolecular pump (10), temperature sensors (32-38) for measuring the stator temperature are arranged. The control device (42) comprises a maximum output power detecting device (50) determining the permissible maximum motor output power in dependence on the measured stator temperature. Thus, the permissible maximum motor output power is not set to a constant value but always fixed in dependence on the stator temperature. Thereby, the capacity of the motor can be fully utilized as long as the measured stator temperature lies below a maximum value.

Abstract: A method is disclosed for categorizing an operating mode of a gas turbine comprising: monitoring at least one operating condition of the gas turbine; using the operating condition to categorize an operating mode of the gas turbine into one of the plurality of predetermined operating modes, and assigning a value to the categorized operating mode where the value is a number that is a power of a predetermined base number.

Abstract: A system is disclosed for adjusting a gas turbine firing temperature control algorithm and combustion reference temperature algorithms based on exhaust gas temperature, turbine pressure ratio and compressor discharge temperature for water content in the air entering the compressor differing from the design water content of ambient air. The water content in the ambient air is calculated by the control system from measured data from a dry bulb temperature sensor and a wet bulb temperature or humidity sensor.

Abstract: In order to provide a stall prediction method for an axial flow compressor, a high response pressure sensor is provided in a duct wall adjacent to the leading edge of the rotor blade and a rotating stall is predicted by computing autocorrelation of pressure data obtained as a time history data. The initiation of rotating stall is determined when the autocorrelation of the time history data starts dropping rapidly. When it is determined that the rotating stall is imminent, generation of the rotating stall is prevented by taking necessary countermeasures such as to reduce the fuel supply.

Abstract: To provide a vacuum pump used for semiconductor manufacturing, which has improved reliability and safety and in which damages to a pump casing, peripheral apparatuses, or the like are prevented from occurring by preventing the occurrence of rotor breakage due to corrosion. A balancer is provided in the outer circumferential surface of the rotor so as to face the inside of the gas passageway. A balancer main body is supported against the outer circumferential surface of a rotor through a fragile portion that is weak with respect to corrosive gasses, the fragile portion of the balancer is damaged by corrosion before any corrosive gas influence appears in rotor blades or the rotor, and the balancer falls off, thus forcibly causing an unbalanced state to appear in the rotor. The balancer thus possesses a function for balancing the rotor and a corrosion detecting function.

Abstract: DC motor rotation speed alarm circuitry includes an input node, a connection node, a ground node, a comparison circuit and a signal generator. When the rotation speed of the DC motor changes during operation, floating voltage is generated between the driving circuit and the ground node. If the floating voltage is less than a preset voltage of the comparison circuit, the alarm signal outputted by the signal generator indicates that the DC motor is operating normally. If the floating voltage is greater than the preset voltage of the comparison circuit, the alarm signal outputted by the signal generator indicates that the DC motor is operating abnormally.

Abstract: A method is disclosed for categorizing an operating mode of a gas turbine comprising: monitoring at least one operating condition of the gas turbine; using the operating condition to categorize an operating mode of the gas turbine into one of the plurality of predetermined operating modes, and assigning a value to the categorized operating mode where the value is a number that is a power of a predetermined base number.

Abstract: An illuminant electric fan mainly comprises a base frame, a fan blade assembly and a plurality of LED lamps, in which the fan blade of the fan blade assembly is mounted and rotates in the tunnel bracket of the base frame to achieve air convection and heat dissipation. The fan blade is made of the luminous material to affect the luminance. Around the rim of the fan tunnel is decorated with a plurality of insert holes to be filled with the LED lamps too. The LED lamps are linked in series to a PCB, which serves the power supply and control over the rotation of the electric fan blade and the lighting of the LED lamps. The light beam emitted from the LED lamp will refract and radiate to produce a wonderful vision.

Abstract: A gas turbine engine (10) comprises a fan rotor (26) having a plurality of fan blades (24) and an apparatus (34) for detecting damage to the fan blades (24). The apparatus (34) comprises a transducer (36) arranged to detect the pressure in the gas flow around the fan blades (34) and to produce a pressure signal. A speed sensor (48) is arranged to measure the speed of rotation of the fan rotor (26) and to produce a speed signal. A processor unit (40) analyses the pressure signal and the speed signal to detect changes in the amplitude of the pressure signal, which occur at multiples of the rotational frequency of the fan rotor (24). The changes indicate differences in pressure between the gas flow around a damaged fan blade (24) and the gas flow around the remainder of the fan blades (24). The processor unit (40) sends a signal indicative of damage to a fan blade (24), if the difference in pressure is above the predetermined level, to an indicator device (44, 46).

Abstract: In the method for the determination of the pressure (p) in and/or of the through-flow (Q) of a liquid through a pump having at least one magnetic bearing for the axial journaling of the pump rotor (1), axial forces act on the rotor (1) of the pump during operation. The axial forces which act on the rotor are utilised for the determination of the pressure (p) and/or of the through-flow (Q).

Abstract: A method and apparatus for detecting the occurrence of surge or incipient surge in a centrifugal compressor is supplied. The centrifugal compressor has an inlet passage, an inlet passage wall and an impeller. When flowing a fluid through the centrifugal compressor thereby establishing a fluid flow in the inlet passage, the fluid flow is measured in the inlet passage proximate the inlet passage wall and proximate the impeller. The measurements may include detecting a reverse in the fluid flow direction, measuring a tangential component to the fluid flow, measuring a substantial decrease in the axial fluid flow, and/or measuring the fluid temperature. Fluid flow in the compressor can then be modified or controlled to prevent surge.

Abstract: Supports are provided on the upper outer casing of each turbine of a turbine unit, and the upper inner casing of the turbine is temporarily placed on the supports of the upper outer casing, which is temporarily placed on the operating floor. By placing the casings temporarily in that way, a large space can be secured for the inspection of the turbine unit, and the inspection can be carried out quickly, which increases the operating ratio of the whole plant including the turbine unit. This invention is useful mainly for turbine units and their overhaul.

Abstract: The broken shaft detection system and method uses a detector assembly mounted downstream of a power turbine wheel of a gas turbine engine to detect rearward axial motion of the wheel and thereby a broken shaft event. The detector assembly has a plunger positioned to be axially displaced against a link connected in an electrical circuit. The link may be broken when the plunger is displaced thereby creating an open circuit that may be detected by a detection and test element. The breaking may be communicated to an overspeed circuit that controls a shut off switch that interrupts fuel flow to the engine. The link may be connected to the detection and test element by two pairs of parallels wires to facilitate monitoring of circuit function and to detect failures that are not broken shaft event failures.

Abstract: A on-line method is provided for detecting wear and/or damage to gas turbine parts. Preferred embodiments of the invention provide a gas turbine comprising parts with smart coatings and collection and detection means to measure wear and erosion of gas turbine parts. In other preferred embodiments, smart coatings are provided comprising chemical taggants that can be collected and detected downstream, thus providing an on-line or in situ evaluation technology for wear and damage to gas turbine parts.

Abstract: A turbine controls testing device is disclosed that can be adapted to test the control systems of most turbine rotors without the use of steam. The turbine controls testing device comprises an operator control system, a drive motive power assembly and a purge gas assembly. The novel device controllably spins, accelerates, and decelerates a turbine with a relatively high level of precision, minimizing the likelihood that, in the event an overspeed mechanism malfunction occurs, the turbine will be damaged as a result of sonic velocity or any other mechanical failure.

Abstract: To prevent surge of a turbocompressor (K), a anti-surge valve (27) provided at the compressor outlet is controlled by a controller (R). The input signal for the controller (R) is generated as a function of the instantaneous flow and the end pressure of the compressor (K) such that the controller responds more slowly to working point shifts in the direction of the surge limit line and more rapidly to working point shifts in the opposite direction. This is achieved by arranging an asymmetric time element or a gradient sensor in the circuit generating the input signal for the controller (R).

Abstract: A gas turbine engine including a temperature sensor assembly that continuously monitors an operating temperature within a multi-stage rotor assembly of the turbine engine is described. A plurality of cavities are defined within the multi-stage rotor assembly. The temperature sensor assembly includes a plurality of temperature sensor assemblies that monitor the temperature within each of the rotor assembly cavities. Each temperature sensor assembly includes a plurality of support guide tubes attached to the engine and extending from an outer casing of the engine to each cavity. A temperature sensor is inserted through the guide tubes and positioned within each cavity.

Abstract: A method is provided to determine an rpm profile for a turbine pump from pulse train data obtained from a sensor at the pump. The method eliminates ramp-up spikes from the pulse train by comparing the spike pulse count to the surrounding pulse counts and replacing data points responsible for abnormal pulse count increases/decreases between data points with interpolated values. The method similarly replaces data points that lie outside statistically acceptable pulse rate variations. A rough rpm plot is then generated, which must be smoothed to obtain the final rpm profile. Data points are infused between sensor data points to achieve an acquisition rate of approximately 1000 points per second. The infusion is accomplished by interpolating between sensor data points and equally spacing the infused data points along the interpolated curve. A smoothing function is then applied to the infused data set.

Abstract: Use of an optical fiber for the direct receipt of heat radiation for transmission to a remote pyrometer is enabled by the provision of an apertured, contaminant free compartment in the component being heated, and aligning the heat receiving end of the optical fiber with the aperture so as to receive radiated heat from within the compartment.

Abstract: An electrical appliance housing is disclosed having a housing with an open side portion and an open front portion adjacent and perpendicular to the open side portion. A removable end panel is provided to fit within the open side portion of the housing and may include an elastically deformable detent mechanism on the side edges of the end panel to temporarily lock it to the housing. An interchangeable modular component is provided within the housing for establishing the function of the electrical appliance housing. The electrical appliance housing function may include air conditioning, air moving, light emitting, infrared light emitting or any other function desirable in a ceiling or wall appliance. The modular components are interchangeable, such that the function of the electrical box may be changed at any time by interchanging the modular components within the housing to the desired set-up.

Abstract: An inspection apparatus for water flow testing of cooling passageways in gas turbine buckets provides observable visual determination of whether any blockages were formed during the manufacturing or refurbishing processes. The inspection apparatus includes a manifold block and manifold control valve mounted on a platform and adapted to engage the root end of a turbine bucket and supply fluid therethrough. The turbine bucket is affixed to the platform with a holder. The fluid exiting at the tip of the turbine bucket is visible and any blockages in the passageways will be easily discerned by the absence or paucity of fluid flow at the tip. Fluid is supplied to the manifold block by a pressure regulated fluid supply line with a control valve and a flow meter. An air supply line is also connected to the manifold block to supply air through the passageways to remove residual fluid from the bucket.

Abstract: A stall precursor detector system for an axial flow compressor having at least one optical sensor to detect the deflection of a rotating airfoil of the compressor, means for comparing the deflection with a predetermined value, the predetermined value being indicative of onset of a stall in the compressor; and means for identifying onset of a stall and producing a stall onset signal if the deflection is greater than the predetermined value. A method for detecting a stall onset in an axial flow compressor system comprising (a) providing at least one optical sensor to measure the deflection of an airfoil, the deflection caused by a rotating stall cell; (b) comparing the deflection as measured in step (a) with a predetermined value indicative of a stall; and (c) identifying onset of a stall if the measured deflection is greater than the predetermined value.

Abstract: There is provided a magnetically levitated apparatus wherein an impeller has one side supported by an electromagnet and the other side supported and magnetically levitated by an attractive force created between a permanent magnet and a permanent magnet of a motor rotor rotated by a motor stator to rotate the impeller and a magnetic bearing sensor provides an output which is in turn rectified and thus shifted to have a gain adjusted and subsequently a notch filter removes a carrier wave frequency component used in the magnetic bearing sensor, to prevent a PID compensator from causing voltage saturation attributed to high frequency noise.

Abstract: A gas turbine engine borescope plug including a retainer that facilitates extending the useful life of the borescope plug is described. The borescope plug seals a pair of opposing inspection port openings in at least two respective spaced-apart walls and maintains sealing contact despite differential thermal growth between the two walls. The borescope plug includes the retainer, a plunger, and a biasing mechanism. The plunger extends through the biasing mechanism and the retainer. The retainer contacts the cylindrical biasing mechanism and maintains its position relative to the plunger to prevent contact between the plunger and the biasing mechanism.

Abstract: A power control system for driving a vessel (which may be manned or unmanned) is used to provide a series of pulse trains to the system wherein at least one pulse within each series of pulse trains provides a differing amount of power. Preferably, a portion of the series of pulse trains which has a duration of 10% of the duration of the pulse train delivers more than 20% of the total power to the drive member for the vessel which the drive member receives each cycle. In this way, the noise signature of a vessel is reduced or is varied to match the noise signature of another vessel or wildlife of a natural phenomenon.

Abstract: A guide tube is fixed adjacent opposite ends in outer and inner covers of a nozzle stage segment. The guide tube is serpentine in shape between the outer and inner covers and extends through a nozzle vane. An insert is disposed in the nozzle vane and has apertures to accommodate serpentine portions of the guide tube. Cooling steam is also supplied through chambers of the insert on opposite sides of a central insert chamber containing the guide tube. The opposite ends of the guide tube are fixed to sleeves, in turn fixed to the outer and inner covers.

Abstract: An instability detecting device, used for easily and simply detecting a rotating stall and/or a surge frequently occurring during an operation of a turbo compressor, is disclosed. The detecting device of this invention has a detector (20) consisting of a body (22). First and second pressure tubes (25) and (26) are axially set in the body (22) while parallely extending on the same plane, with first and second pressure discharge ports (25a) and (26a) of the first and second pressure tubes exposed to the outside of the body (22) at an end surface of the body (22). A partition wall (28) is arranged on the end surface of the body (22) while crossing the end surface and separating the first and second pressure discharge ports (25a) and (26a) from each other.

Abstract: To reduce losses by exerting the exhaustion performance to the full extent when a temperature of a rotor blade is within an allowable value, and to lower a variation in an r.p.m. of a turbomolecular pump even with a change in the gas load to maintain the exhaustion performance. Further to prevent deterioration of the rotor blade caused by a heat generation when a temperature of a rotor blade exceeds an allowable value. A driver output set r.p.m. determining unit 5 determines a driver output which can be exerted to the maximum or a set r.p.m., in response to signals of rotor blade temperature sensor 1, an r.p.m. sensor 2, a motor current sensor 3, and an axial electromagnet current sensor 4 when the temperature of the rotor blade is within an allowable value. A driver output switching unit 6 changes over a turbomolecular pump driving output of a motor driver 8, in response to the signal of the driver output set r.p.m. determining unit 5. Further, an r.p.m. compensating unit 7 changes a driving r.p.m.